1,898 research outputs found
Incentives-Based Mechanism for Efficient Demand Response Programs
In this work we investigate the inefficiency of the electricity system with
strategic agents. Specifically, we prove that without a proper control the
total demand of an inefficient system is at most twice the total demand of the
optimal outcome. We propose an incentives scheme that promotes optimal outcomes
in the inefficient electricity market. The economic incentives can be seen as
an indirect revelation mechanism that allocates resources using a
one-dimensional message space per resource to be allocated. The mechanism does
not request private information from users and is valid for any concave
customer's valuation function. We propose a distributed implementation of the
mechanism using population games and evaluate the performance of four popular
dynamics methods in terms of the cost to implement the mechanism. We find that
the achievement of efficiency in strategic environments might be achieved at a
cost, which is dependent on both the users' preferences and the dynamic
evolution of the system. Some simulation results illustrate the ideas presented
throughout the paper.Comment: 38 pages, 9 figures, submitted to journa
Hamlet and Marginality
This research aims to explore the place of marginality (or that which is not the immediate focus of narrative) in the context of the play and through the examination of the characters of Fortinbras and Horatio, in William Shakespeare’s Hamlet. The intended outcome is to encourage diversified perspectives and approaches to the play by focusing on the marginal themes and/or characters.
The chapters address the characters of Fortinbras and Horatio; the first inverts the protagonist/foil relationship by reading Hamlet as a foil to Fortinbras, while the second uses Freud’s “The Uncanny” as a way to understand Horatio’s role in the play, as its uncanniest phenomena. Both are marginal to the text, but both are significant to the understanding of the text.
Essentially, the objective is to encourage readings of the play, and of narratives, that appreciate the complexity of marginality, in order to broaden the language for future research
Anomaly detection on data streams from vehicular networks
As redes veiculares são compostas por nós com elevada mobilidade que apenas estão ativos quando o veículo se encontra em movimento, tornando a rede imprevisível e em constante mudança. Num cenário tão dinâmico, detetar anomalias na rede torna-se uma tarefa exigente, mas crucial. A Veniam opera uma rede veicular que garante conexão fiável através de redes heterogéneas como LTE, Wi-Fi e DSRC, conectando os veículos à Internet e a outros dispositivos espalhados pela cidade. Ao longo do tempo, os nós enviam dados para a Cloud tanto por tecnologias em tempo real como por tecnologias tolerantes a atraso, aumentando a dinâmica da rede.
O objetivo desta dissertação é propor e implementar um método para detetar anomalias numa rede veicular real, através de uma análise online dos fluxos de dados enviados dos veículos para a Cloud. Os fluxos da rede foram explorados de forma a caracterizar os dados disponíveis e selecionar casos de uso. Os datasets escolhidos foram submetidos a diferentes técnicas de deteção de anomalias, como previsão de séries temporais e deteção de outliers baseados na densidade da vizinhança, seguido da análise dos trade-offs para selecionar os algoritmos que melhor se ajustam às características dos dados. A solução proposta engloba duas etapas: uma primeira fase de triagem seguida de uma classificação baseada no método dos vizinhos mais próximos.
O sistema desenvolvido foi implementado no cluster distribuído da Veniam, que executa Apache Spark, permitindo uma solução rápida e escalável que classifica os dados assim que chegam à Cloud.
A performance do método foi avaliada pela sua precisão, i.e., a percentagem de verdadeiras anomalias dentro das anomalias detetadas, quando foi submetido a datasets com anomalias artificiais provenientes de fontes de dados diferentes, recebidas tanto por tecnologias em tempo real como por tecnologias tolerantes a atraso.Vehicular networks are characterized by high mobility nodes that are only active when the vehicle is moving, thus making the network unpredictable and in constant change. In such a dynamic scenario, detecting anomalies in the network is a challenging but crucial task. Veniam operates a vehicular network that ensures reliable connectivity through heterogeneous networks such as LTE, Wi-Fi and DSRC, connecting the vehicles to the Internet and to other devices spread throughout the city. Over time, nodes send data to the cloud either by real time technologies or by delay tolerant ones, increasing the network's dynamics.
The aim of this dissertation is to propose and implement a method for detecting anomalies in a real-world vehicular network through means of an online analysis of the data streams that come from the vehicles to the cloud. The network's streams were explored in order to characterize the available data and select target use cases. The chosen datasets were submitted to different anomaly detection techniques, such as time series forecasting and density-based outlier detection, followed by the trade-offs' analysis to select the algorithms that best modeled the data characteristics. The proposed solution comprises two stages: a lightweight screening step, followed by a Nearest Neighbor classification.
The developed system was implemented on Veniam's distributed cluster running Apache Spark, allowing a fast and scalable solution that classifies the data as soon as it reaches the Cloud.
The performance of the method was evaluated by its precision, i.e., the percentage of true anomalies within the detected outliers, when it was submitted to datasets presenting artificial anomalies from different data sources, received either by real-time or delay tolerant technologies
A Platform-Based Software Design Methodology for Embedded Control Systems: An Agile Toolkit
A discrete control system, with stringent hardware constraints, is effectively an embedded real-time system and hence requires a rigorous methodology to develop the software involved. The development methodology proposed in this paper adapts agile principles and patterns to support the building of embedded control systems, focusing on the issues relating to a system's constraints and safety. Strong unit testing, to ensure correctness, including the satisfaction of timing constraints, is the foundation of the proposed methodology. A platform-based design approach is used to balance costs and time-to-market in relation to performance and functionality constraints. It is concluded that the proposed methodology significantly reduces design time and costs, as well as leading to better software modularity and reliability
Estimación de la curva de Phillips para Colombia, periodo mensual 2001 - 2007
Este artículo describe y analiza las relaciones existentes entre el desempleo y la inflación y su impacto sobre la economía colombiana, a través de la estimación de la curva de Phillips para el período mensual 2001-2007, mediante la evaluación por mínimos cuadrados de una función lineal con un término Autorregresivo (AR(1)).Los resultados obtenidos concuerdan con una curva de Phillips de pendiente positiva aparentemente contraria a la teoría económica tradicional, pero a la vez congruente con la teoría Austríaca del ciclo económico. De acuerdo a lo arrojado por el análisis econométrico y estadístico, si la tasa de desempleo aumenta en 1%, la inflación hará lo propio en 7.79%.Desempleo, Inflación, curva de Phillips, Política monetaria, Política Fiscal, Teoría del ciclo económico, pendiente positiva.
Underutilization of workers: an analysis according to the lean management philosophy in basic education
One of the eight wastes that Lean production, inspired by the Toyota Production System, proposes to study is the underutilization of workers, that is, the inadequate use of their intelligence. The sense is to provide listening and participation in improvement projects, of professionals who have experience in daily life and, in many cases, consistent academic qualifications. The objective of this work is to study the importance of the participation of teachers and employees of a basic education school in the construction of new routines and work methods, in the context of the Lean management philosophy, justified by the scarcity of scientific literature on the subject. Brazil has about 184,000 basic education schools with one million four hundred thousand teachers working from kindergarten to the ninth grade of elementary school, and of these, 83.2% have a college degree, a percentage that grows every year. About the schools, 21.7% are private, 61.3% municipal, 16.6% state, and 0.4% are federal schools. As a research methodology, a systematic review of the literature was adopted, based on the PRISMA protocol, allowing the identification of 53 records, 14 of which were included in the literature review, due to their adherence to the researched subject. The main contribution of this paper is the identification of a research gap involving the underutilization of workers and adoption of the Lean management philosophy in the education sector, as well as a conceptual proposal of the positive impact on the educational organization results by not underutilizing workers, without wasting their intelligence
Optimization of blueberry flour processing and anthocyanin extraction
O objetivo deste trabalho foi determinar as condições ideais para o processamento da farinha e a extração de antocianinas de mirtilos (Vaccinium corymbosum). Utilizou-se um delineamento composto central (DCC) com superfícies de resposta. Para o processamento da farinha de mirtilo, utilizaram-se diferentes temperaturas (53ºC–67ºC) e tempos (43,18–48,82 horas) de desidratação. A extração de antocianinas foi feita com soluções de etanol (15–85% v/v) com diferentes valores de pH (1,0–4,0). O teor de antocianinas monoméricas totais foi de 1.538,39±25,63 mg 100 g-1 (valor de desejabilidade de 0,89) para mirtilos frescos, na condição ótima de extração (53,5% etanol, pH 2,5), e de 3.101,04±11,57 mg 100 g-1 (valor de desejabilidade de 0,96) para farinha de mirtilo, na condição ótima de processamento (53ºC, 46 horas). A extração e a desidratação otimizadas dos mirtilos proporcionam a obtenção de altos teores de antocianinas nas amostras.The objective of this work was to determine the ideal conditions for the processing of flour and extraction of anthocyanins from blueberries (Vaccinium corymbosum). A central composite design (CCD) with response surfaces was used. For the processing of blueberry flour, different dehydration temperatures (53ºC–67ºC) and times (43.18–48.82 hours) were used. The extraction of anthocyanins was performed with ethanol solutions (15–85% v/v) at different pH values (1.0–4.0). ). The total monomeric anthocyanin content was 1,538.39±25.63 mg 100 g-1 (0.89 desirability value) for fresh blueberries in the optimal extraction condition (53.5% ethanol, 2.5 pH) and 3,101.04±11.57 mg 100 g-1 (0.96 desirability value) for blueberry flour in the optimum processing condition (53ºC, 46 hours). The optimized extraction and dehydration of blueberries provide high levels of anthocyanins in the samples
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